1. Field of the Invention
The invention relates to an indexable insert for a milling tool.
The invention relates to an indexable insert for a milling tool for machining crankshafts or camshafts wherein the insert includes at least one mounting surface having a bore for fixing the insert to a rotatable tool part and at least one cutting face forming cutting edges with the lateral surfaces.
Furthermore, the invention relates to a milling tool, in particular, a milling tool for machining crankshafts or camshafts.
2. Discussion of Background Information
Inserts for milling tools, in particular, milling tools for machining crankshafts, generally have a wedge angle of 90°, i.e., the angle on the cutting edge from the side face to the cutting face of the insert. When installed in the milling tool, the cutting angle of the insert is negative and has a value of approx. −8° to −12°. Such an arrangement is known in the art as “negative (insert) geometry.”
In use, the milling tool that utilizes a wedge angle of 90° produces a high edge-holding ability of the insert. However, the negative geometry causes strong cutting forces during cutting.
Furthermore, strong cutting forces on the milling tool subject the transmission drive of the milling cutter to high loads. However, this arrangement must be free from play and may not permit any chatter vibrations at all.
A reduction of the cutting forces acting on an insert and thus a reduction in the load on the milling cutter drive can be achieved, as one skilled in the art is aware, utilizing a so-called positive geometry of the cutting edge. With a cutting angle of less than 90°, a wedge angle of the insert on the cutting edge of 82° to 70° should be provided.
Attempts have been made to use indexable inserts utilizing a cutting cavity recessed from the cutting edge on all sides, and in this manner to create a positive geometry of the cutting edge of the milling tool. Although this geometry of the cutting edge of the insert can largely meet the expectations with respect to a reduction of the cutting forces, and thus cause a reduction of the load on the tool drive (working free from play), it has the disadvantage of being more complicated to produce, has a low cutting edge-holding ability and has an insert geometry associated with high dimensional tolerances and uneven or unmachined sintered bearing surfaces.